Using the Nikon D5100/Handling
Although the family resemblance is obvious, the D5100 does not share the same body shell as its predecessor the D5000. At a casual glance, the two cameras are near-twins, but Nikon has taken the opportunity to completely rearrange the controls on the camera's rear, and the top-plate has been subject to a minor reshuffle as well. It is also worth noting that the D5100 boasts dual IR receivers (front and rear) as opposed to the single receiver of the D5000.
Overall operation and handlingIn general, we like the way that the D5100 handles. Its body design is smaller and neater than its predecessor's and key controls fall easily to hand.
However, it isn't all roses. The new position of the magnification controls, for example, might cause problems for photographers used to the D3100 or D5000. Their former position, stuck out on the extreme left of the camera wasn't exactly optimal, but their new location, on completely the opposite side of the camera, takes some getting used to. It doesn't help that the magnification buttons are smaller than they were on the D5000, and are now positioned perilously close to the delete button.
We're a little disappointed too that the D5100 doesn't inherit the combined live view/movie record thumb switch that appears on the D3100 and D7000. We thought it was a successful arrangement and adopting it here would have left room for a drive mode lever. Some users will also be disappointed that because it lacks an internal AF motor, the D5100 cannot achieve automatic focus with D-type or older optics.
Of more general concern, the D5100 has inherited the odd live view quirk from its sister models that means the aperture is locked when you enter live view - something you need to consider before shooting any video footage. There's also still no indication of exposure if you switch to manual exposure mode in live view. The most obvious difference between the D5100 and its predecessor however, is the addition of a side-hinged LCD screen. The D5000's LCD screen was articulated, but slightly awkwardly, via a hinge at the base of the camera's rear. This caused problems in some shooting positions, especially when the camera was mounted on a tripod. The D5100's screen is hinged in a more conventional way, along its side, which allows it to fold out from the left hand side of the camera. It is fully articulated, which means that the display can also be folded inwards, for protection.
The redesign of the LCD screen has forced some pretty major changes to the D5100's rear control layout. Because of the incorporation of a vertical hinge on its left hand side, the buttons that occupied this position on the D5000 have been moved to the right of the LCD. The play and magnification buttons are now ranged close to the 4-way controller, and the menu and delete buttons have swapped places. The 'i' button, which used to sit to the left of the LCD screen on the rear of the D5000 has moved too, and joins the AE-L/AF-L button on the top right of the camera, alongside the control dial.
Specific handling issues
If we had to summarize the D5100's handling and operation in one sentence, we'd probably say 'like a cross between the D3100 and D7000, without being quite as satisfying as either'. We love the articulated LCD screen, but in a lot of other respects, the decisions that Nikon has made with regards to the industrial design of the D5100 seem almost arbitrary.
Let's start though with the things that Nikon hasn't changed over the D5000 and D3100. One of our biggest gripes about the handling of Nikon's entry level DSLRs when used in conventional eye-level fashion has to do with setting the ISO. This is a parameter that we think should be easy to change with the camera to your eye, using a button that's easily identified by feel alone, and without having to shift your grip on the camera with either hand.
On the D5100, just like the D3100 and the D5000 before it, the only way to change ISO via an external control is to assign it to the 'Fn' button. This is reasonably well-placed for operation by your left thumb with the camera to your eye, but because of its close proximity and identical shape to the flash button, the two are still easily confused when working by feel alone. This means it's all-too-easy to pop the flash up by mistake when you meant to change the sensitivity. We'd be much happier to see ISO operated using the button currently assigned to 'info', which is a function you never need to access with the camera to your eye.
Also unchanged is the D5100's auto ISO functionality. Whereas all other brands program Auto ISO in a fashion that's designed to combat camera shake (or blur from relatively slowly-moving subjects) by automatically increasing the ISO at a shutter speed determined by the focal length of the lens, Nikon's approach uses a single, user-specified minimum shutter speed, which has to be carefully selected for the specific situation and focal length being used. To be fair this method has a real advantage for sports and action work, but it also makes Auto ISO distinctly unsuited to general 'walkaround' use with a zoom lens.
The design changes that Nikon has made in the D5100 have created some brand new issues as well. We've already mentioned the odd grouping of the image magnification buttons alongside 'delete', but more disappointing in normal use is the absence of the D3100's rather neat drive mode switch, on the top plate. Instead, this area of the D5100 is occupied by a physical live view switch. Unlike the D3100 however, the D5100's live view switch lacks an integrated movie shooting button. Instead, this button is 'orphaned' on its own to the left of the shutter release. The movie shooting button serves no function whatsoever unless the camera is in live view mode, and it cannot be customized. The general impression is of a camera whose second-tier control points seem to have been arranged almost randomly.